1. Field of the Invention
The present invention relates to a cleansing composition, which is mild to the skin and eyes and possesses sufficient viscosity with appropriate cleansing and foaming performance.
2. Description of the Prior Art
Historically, many mild cleansing compositions suffer from poor foaming and cleansing performance. As used herein, the term xe2x80x9cmild cleansing compositionsxe2x80x9d refer to compositions that, when instilled into human eyes at about a 10% dilution level, cause an ocular irritation that is less than or equivalent to the irritation caused by a similar addition of sterile water thereto. In many cases, the ocular stinging effect of a composition on the eye is concentration dependent. Therefore, one way to reduce ocular irritancy is to minimize the amount of the cleansing composition that gets into the eye via increasing the viscosity of the product. For example, the viscosity of a shampoo may be sufficiently increased in order to minimize the amount that may drip from the head into the eyes during its use. However, it can be difficult or costly to thicken shampoos.
One known method for thickening mild cleansing compositions is via the addition of a viscosity builder such as a salt, e.g. sodium chloride, to a cleansing composition. However, the use of sodium chloride at high levels negatively impacts eye irritation. Another method for thickening mild cleansing compositions is via the addition of polymeric thickeners such as hydroxyethyl cellulose to the composition. Unfortunately, many of the polymeric thickeners are incompatible with surfactant systems and therefore contribute to instability of the final product. Yet another popular method for thickening mild cleansing compositions is via the addition of a polyol alkoxy ester to the composition. In each of these approaches, the compound is added merely to build viscosity of the cleansing system, thereby adding cost while contributing little else to the performance of the system.
A better approach to the problem is to incorporate surfactants that both build viscosity and contribute to the foaming and cleansing performance of the surfactant system while maintaining low cost. One such class of surfactants that have been used extensively for this purpose includes the alkanolamides, such as the fatty acid diethanotamides. The use of ethoxylated diethanolamines as irritancy mitigators has been described in U.S. Pat. No. 4,336,151. In U.S. Pat. No. 4,205,063, the use of fatty acid diethanolamide has been described in low irritation shampoo formulas as a foam booster. Unfortunately, the use of diethanolamides in cosmetic preparations has recently come under scrutiny due to safety concerns regarding their possible carcinogenicity.
Therefore, there is a need for a cosmetic ingredient that is capable of viscosity building and foam boosting without compromising the mildness and safety properties of the overall cleansing composition.
It has been discovered that the aforementioned objective can be achieved by selecting specific compounds to increase the viscosity while building the foam of a cleansing composition. The present invention provides a cleansing composition including a compound of formula I 
wherein: R=C6 to C30 Fatty Acid, n=0 to 20, m=0 to 40, and n+m=2 to 60; and at least one anionic surfactant; wherein the composition is mild.
The cleansing composition of the present invention is comprised of, consists of, and/or consists essentially of, based upon the total weight of the composition, a) from about 0.01% to about 10.0%, e.g. from about 0.1% to about 7.0% and from about 0.5% to about 3.0% of the compound of Formula I. and b) from about 0.1% to about 20%, e.g. from about 0.5% to about 10% and from about 0.75% to about 5% of an anionic surfactant.
The compound of Formula I may be selected from ethoxylated fatty amides, propoxylated fatty amides, fatty amides that contain both ethoxylate and propoxylate groups, and mixtures thereof. Suitable compounds include, but are not limited to, polyethylene glycol (xe2x80x9cPEGxe2x80x9d)-6 Cocamide, PEG-6 Lauramide, PEG-3 Cocamide, polypropylene glycol (xe2x80x9cPPGxe2x80x9d)-2 Hydroxyethyl Cocamide, PPG-1 Hydroxyethyl Caprylamide, and PPG-3 Hydroxyethyl Linoleamide. The preferred compounds include PPG-2 Hydroxyethyl Cocamide, which is available from Uniqema under the tradename, xe2x80x9cPromidium COxe2x80x9d, PPG-1 Hydroxyethyl Caprylamide, which is available from Uniqema under the tradename, xe2x80x9cPromidium CCxe2x80x9d, PPG-3 Hydroxyethyl Linoleamide, which is available from Uniqema under the tradename, xe2x80x9cPromidium SYxe2x80x9d, and PEG-3 Cocamide, which is available from Heterene, Inc. under the tradename, xe2x80x9cHetoxamide CD-4.xe2x80x9d
Classes of anionic surfactants useful in this invention include the alkyl sulfates, alkyl ether sulfates, sulfosuccinates, isethionates, acyl amides, alkyl ether carboxylates and alkyl phosphates, wherein the alkyl group has from about 6 carbon atoms to about 30 carbon atoms, with about 10 to about 14 carbon atoms being preferred.
In addition to at least one anionic surfactant, the mild cleansing composition of the invention may optionally contain a secondary surfactant selected from nonionic, amphoteric, betaine, cationic, and mixtures thereof. The total amount of anionic surfactant and secondary surfactant(s) that are suitable for use in the composition of the present invention may range from, based upon the total weight of the total cleansing composition, from about 2.5% to about 50%, e.g. from about 5% to about 40% and from about 8% to about 25%.
Types of nonionic surfactants that are suitable for use in this invention include the fatty alcohol acid or amide ethoxylates, monoglyceride ethoxylates, sorbitan ester ethoxylates and alkyl polyglycosides. These nonionic surfactants can be employed in composition of the present invention in an amount, based upon the total weight of the composition, from about 0.0% to about 30%, e.g. from about 0.1% to about 20% and from about 0.1% to about 15%.
Classes of amphoteric surfactants that are suitable for use in this invention include alkylimino-diproprionates, alkylamphoglycinates (mono or di), alkylamphoproprionates (mono or di), alkylamphoacetates (mono or di), N-alkyl xcex2-aminoproprionic acids, alkylpolyamino carboxylates, and phosphorylated imidazolines. These amphoteric surfactants can be employed in composition of the present invention in an amount, based upon the total weight of the composition, from about 0.1% to about 20%, e.g. from about 0.1% to about 15% and from about 0.1% to about 10%.
Types of betaines that are suitable for use in this invention include alkyl betaines, alkylamido betaines, alkyl sultaines and alkylamido sultaines, wherein the alkyl group has from about 6 carbon atoms to about 30 carbon atoms, with about 10 to about 14 carbon atoms being preferred. These betaine surfactants can be employed in the cleansing composition of the present invention in an amount, based upon the total weight of the cleansing composition, from about 0.1% to about 15%, e.g. from about 0.1% to about 10% and from about 0.1% to about 8%.
Classes of cationic surfactants that are suitable for use in this invention include alkyl quaternaries (mono, di, or tri), benzyl quaternaries, ester quaternaries, ethoxylated quaternaries, alkyl amines, and mixtures thereof, wherein the alkyl group has from about 6 carbon atoms to about 30 carbon atoms, with about 8 to about 22 carbon atoms being preferred. These cationic surfactants can be employed in composition of the present invention in an amount, based upon the total weight of the composition, from about 0.01% to about 20%, preferably from about 0.05% to about 15% and more preferably from about 0.1% to about 10%.
Optionally, the mild cleansing compositions of this invention may also contain, based upon the total weight of the mild cleansing composition, from about 0.01 percent to about 1.0 percent, preferably from about 0.01 percent to about 0.5 percent, and more preferably from about 0.01 to about 0.2 percent of at least one conditioning agent. Examples of suitable cationic conditioning agents nonexclusively include cationic cellulose derivatives; cationic guar derivatives; and diallyldimethylammonium chloride. Other suitable conditioning agents include those disclosed in U.S. Pat. No. 5,876,705, which is incorporated herein by reference. Surfactant soluble non-volatile silicone conditioning agents are also useful.
The cationic cellulose derivative may be a polymeric quaternary ammonium salt derived from the reaction of hydroxyethyl cellulose with a trimethylammonium substituted epoxide. The material known as Polyquaternium-10, commercially available from Amerchol Corporation of Edison, N.J. as xe2x80x9cPolymer JR-400,xe2x80x9d is especially useful in this regard.
The cationic guar derivative may be a guar hydroxypropyltrimonium chloride, available commercially from Rhodia of Cranbury, N.J. under the tradename, xe2x80x9cJaguar C-17.xe2x80x9d
Other useful cationic conditioning polymers are those derived from the monomer diallyldimethylammonium chloride. The homopolymer of this monomer is Polyquaternium-6, which is available commercially form Allied Colloids of Suffolk, Va. under the tradename, xe2x80x9cSalcare SC30.xe2x80x9d The copolymer of diallyldimethylammonium chloride with acrylamide is known as Polyquaternium-7, and is also available from Allied Colloids under the tradename xe2x80x9cSalcare SC10.xe2x80x9d
The mild cleansing compositions of the present invention may also include one or more optional ingredients nonexclusively including a pearlescent or opacifying agent, a thickening agent, secondary conditioners, humectants, chelating agents, and additives which enhance their appearance, feel and fragrance, such as colorants, fragrances, preservatives, pH adjusting agents, and the like. The pH of the mild cleansing compositions of this invention is preferably maintained in the range of from about 5 to about 7.5, and more preferably from about 5.5 to about 7.0.
Commercially available pearlescent or opacifying agents which are capable of suspending water insoluble additives such as silicones and/or which tend to indicate to consumers that the resultant product is a conditioning shampoo are suitable for use in this invention. The pearlescent or opacifying agent may be present in an amount, based upon the total weight of the composition, of from about 1 percent to about 10 percent, preferably from about 1.5 percent to about 7 percent, and more preferably, from about 2 percent to about 5 percent. Examples of suitable pearlescent or opacifying agents include, but are not limited to mono or diesters of (a) fatty acids having from about 16 to about 22 carbon atoms and (b) either ethylene or propylene glycol; mono or diesters of (a) fatty acids having from about 16 to about 22 carbon atoms (b) a polyalkylene glycol of the formula: HOxe2x80x94(JO)axe2x80x94H, wherein J is an alkylene group having from about 2 to about 3 carbon atoms; and a is 2 or 3;fatty alcohols containing from about 16 to about 22 carbon atoms; fatty esters of the formula: KCOOCH2L, wherein K and L independently contain from about 15 to about 21 carbon atoms; inorganic solids insoluble in the shampoo composition, and mixtures thereof
The pearlescent or opacifying agent may be introduced to the mild cleansing composition as a pre-formed, stabilized aqueous dispersion, such as that commercially available from Henkel Corporation of Hoboken, N.J. under the tradename, xe2x80x9cEuperlan PK-3000.xe2x80x9d This material is a combination of glycol distearate (the diester of ethylene glycol and stearic acid), Laureth-4 (CH3(CH2)10CH2(OCH2CH2)4OH) and cocamidopropyl betaine and preferably is in a weight percent ratio of from about 25 to about 30: about 3 to about 15: about 20 to about 25, respectively.
Commercially available thickening agents, which are capable of imparting the appropriate viscosity to the mild cleansing compositions are suitable for use in this invention. If used, the thickener should be present in the shampoo compositions in an amount sufficient to raise the Brookfield viscosity of the composition to a value of between about 500 to about 10,000 centipoise. Examples of suitable thickening agents nonexclusively include: mono or diesters of 1) polyethylene glycol of formula: HOxe2x80x94(CH2CH2O)zH, wherein z is an integer from about 3 to about 200; and 2) fatty acids containing from about 16 to about 22 carbon atoms; fatty acid esters of ethoxylated polyols; ethoxylated derivatives of mono and diesters of fatty acids and glycerine; hydroxyalkyl cellulose; alkyl cellulose; hydroxyalkyl alkyl cellulose; and mixtures thereof. Preferred thickeners include polyethylene glycol ester, and more preferably PEG-150 distearate which is available from the Stepan Company of Northfield, Ill. or from Comiel, S.p.A. of Bologna, Italy under the tradename, xe2x80x9cPEG 6000 DSxe2x80x9d.
Commercially available secondary conditioners, such as volatile silicones, which impart additional attributes, such as gloss to the hair are suitable for use in this invention. Preferably, the volatile silicone conditioning agent has an atmospheric pressure boiling point less than about 220xc2x0 C. The volatile silicone conditioner may be present in an amount of from about 0 percent to about 3 percent, preferably from about 0.25 percent to about 2.5 percent, and more preferably from about 0.5 percent to about 1.0 percent, based on the overall weight of the composition. Examples of suitable volatile silicones nonexclusively include polydimethylsiloxane, polydimethylcyclosiloxane, hexamethyldisiloxane, cyclomethicone fluids such as polydimethylcyclosiloxane available commercially from Dow Coming Corporation of Midland, Mich. under the tradename, xe2x80x9cDC-345xe2x80x9d and mixtures thereof, and preferably include cyclomethicone fluids.
Commercially available humectants, which are capable of providing moisturization and conditioning properties to the mild cleansing composition, are suitable for use in the present invention. The humectant may be present in an amount of from about 0 percent to about 10 percent, preferably from about 0.5 percent to about 5 percent, and more preferably from about 0.5 percent to about 3 percent, based on the overall weight of the composition. Examples of suitable humectants nonexclusively include: 1) water soluble liquid polyols selected from the group comprising glycerine, propylene glycol, hexylene glycol, butylene glycol, dipropylene glycol, and mixtures thereof; 2)polyalkylene glycol of the formula: HOxe2x80x94(Rxe2x80x3O)bxe2x80x94H, wherein Rxe2x80x3 is an alkylene group having from about 2 to about 3 carbon atoms and b is an integer of from about 2 to about 10; 3) polyethylene glycol ether of methyl glucose of formula CH3-C6H10O5xe2x80x94(OCH2CH2)cxe2x80x94OH, wherein c is an integer from about 5 to about 25; 4) urea; and 5) mixtures thereof, with glycerine being the preferred humectant.
Examples of suitable chelating agents include those which are capable of protecting and preserving the compositions of this invention. Preferably, the chelating agent is ethylenediamine tetracetic acid (xe2x80x9cEDTAxe2x80x9d), and more preferably is tetrasodium EDTA, available commercially from Dow Chemical Company of Midland, Mich. under the tradename, xe2x80x9cVersene 100XLxe2x80x9d and is present in an amount, based upon the total weight of the composition, from about 0 to about 0.5 percent, and preferably from about 0.05 percent to about 0.25 percent.
Suitable preservatives include Quaternium-15, available commercially as xe2x80x9cDowicil 200xe2x80x9d from the Dow Chemical Corporation of Midland, Mich., and are present in the composition in an amount, based upon the total weight of the composition, from about 0 to about 0.2 percent, and preferably from about 0.05 percent to about 0.10 percent.
The above described mild cleansing composition may be prepared by combining the desired components in a suitable container and mixing them under ambient conditions in any conventional mixing means well known in the art, such as a mechanically stirred propeller, paddle, and the like. Although the order of mixing is not critical, it is preferable to pre-blend certain components, such as the fragrance and the nonionic surfactant before adding such components into the main mixture.
The compositions of the present invention are preferably used in personal care products such as shampoos, washes, baths, gels, lotions, creams, and the like.
The invention illustratively disclosed herein suitably may be practiced in the absence of any component, ingredient, or step which is not specifically disclosed herein. Several examples are set forth below to further illustrate the nature of the invention and the manner of carrying it out. However, the invention should not be considered as being limited to the details thereof.